The principle of the screen printing is that ink can pass through meshes in graphic portions of a screen printing plate but cannot pass through non-graphic portions of the screen printing plate. A screen printing machine generally includes a screen printing plate, a squeegee, an ink tank and a carrying platform. The screen plate is a flat plate and is placed on the carrying platform. The squeegee is located at one side of the screen plate away from the carrying platform. At beginning of starting, ink is poured to one end of the screen printing plate, pressure is applied to the ink at the screen printing plate by moving the squeegee from one end to the other end of the screen printing plate, thereby moving the ink along a surface of the screen printing plate and squeezing the ink out of the meshes in graphic portions. During the process of printing, a gap is kept between the screen printing plate and a printing stock; since a movable line contact is provided between the screen printing plate and the squeegee, and the pressure applied by the squeegee to the screen printing plate can cause a movable line contact between the screen printing plate and the squeegee. Then, the ink is separated from the screen printing plate at the contact line between the screen printing plate and the printing stock and thus is stick to the printing stock, thereby achieving the printing process. Thus, the above printing machine can ensure printing size accuracy, and can prevent the printing stock from being soiled by the ink. However, during the printing process, the screen printing plate works under a certain pressure applied by the squeegee, and thus the screen printing plate is easily damaged.